I've got a Nishiki backroads aluminum mountain bike. Not a very high end bike ( 10 years ago it cost me $250) but it has done me well over the years. Recently while riding a small stick caught up in the rear derailer and the next thing I knew I was walking. It seems the stick bent the bracket the derailer mounts to right across the hole at not quite a 45 degree radiused angle. The derailer was pried from the bracket. The bike is all aluminum and it appears that there was a helicoil or some type of hard metal threading in the aluminum that came out with the derailer mounting bolt. Any suggestions for repair? I have found a thread repair kit for a metric 10 x 1.0 bolt. Will the aluminum take straightening and new threads inserted or will it be too brittle? Is it worth the time and effort? The local bike shop was not very interested in attempting a repair. There are some bigger shops in town I haven't checked with yet. What do you experienced guys think?